JP2774537B2 - Heat fixing method and heat fixing toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat fixing method and a heat fixing method for fixing a visible image formed by a toner in a recording medium such as electrophotography, electrostatic printing, and magnetic recording. It relates to the toner used.

[Prior art] Conventionally, as a method for fixing a visible image of a toner to a recording material, a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and pressing against the heating roller are undetermined. A hot roll fixing method in which a recording material holding an attached toner visible image is heated while being nipped and conveyed is often used.

Also, a belt fixing system described in US Pat. No. 3,578,797 is known.

[Problems to be solved by the invention]

However, in the above-described conventional hot roll fixing, (1) there is a so-called wait time during which the image forming operation is prohibited until the heat roller reaches a predetermined temperature.

(2) The heating roller is maintained at an optimum temperature in order to prevent a fixing failure due to a change in the temperature of the heating roller due to the passage of the recording material or other external factors and a transfer of toner to the heating roller, that is, an offset phenomenon. Need
For this purpose, the heat capacity of the heating roller or the heating element must be increased, which requires a large amount of electric power and causes a rise in the temperature of a system such as electrophotography in the apparatus.

(3) When the recording material is discharged through the heating roller because the roller is at a constant temperature, the recording material and the toner on the recording material are cooled slowly, so that the toner has a high tackiness, May be offset, or a paper jam may occur due to the recording material being entangled.

(4) The configuration is such that the high-temperature heating roller is directly in contact with the hand, which causes a problem in safety or requires a protection member.

Further, even in the belt fixing system described in US Pat. No. 3,578,797, the above-mentioned problems (1) and (2) of hot roll fixing have not been fundamentally solved.

[Object of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to substantially eliminate the above-mentioned problems, or to have a very short wait time, a low power consumption, no offset phenomenon, and a good fixation of a toner image on a recording material. An object of the present invention is to provide a novel heat fixing method.

Another object of the present invention is to provide a heat fixing toner which is preferably used in the heat fixing method provided in the present invention.

Still another object of the present invention is to provide a heat fixing method which does not use a high-temperature rotating roller and does not require a heat-resistant special bearing.

Still another object of the present invention is to provide a heat fixing method which is excellent in safety or does not require a protective member by having a fixing device configuration which does not directly touch the high-temperature body.

In Japanese Patent Application No. 62-144784 previously proposed by the present applicant, a toner visible image is heated via a heat-resistant sheet that is moved by a low-heat-capacity heating element that is energized and heated in a pulse form, and is fixed on a recording material. An image forming apparatus which has a short wait time and low power consumption depending on a fixing device to be used has been proposed. Similarly, in Japanese Patent Application No. 63-12069 previously proposed by the present applicant, in a fixing device for heating and fixing a visible image of a toner to a recording material via a heat-resistant sheet, the heat-resistant sheet has a heat-resistant layer. There has been proposed a fixing device having a release layer or a low-resistance layer to effectively prevent the offset phenomenon.

However, in order to achieve an excellent fixing method of toner visible images on a recording material, prevention of offset, etc., and a fixing method with a short wait time and low power consumption, in addition to the fixing device as described above, Greatly depends on the characteristics of the toner.

[Means for solving the problem]

 The above object is achieved by the present invention described below.

That is, the present invention relates to a heat fixing method for heating and fixing a visible image of the toner on a recording material by using a toner containing at least a binder resin and a colorant, wherein: a) an aromatic vinyl monomer and an acrylate monomer; And a polymer formed from one or more monomers selected from the group consisting of methacrylate monomers as a binder resin, wherein the binder resin has a THF-insoluble content based on the weight of the binder resin. As 10 ~ 6
Using a toner containing 0% by weight, b) a heating body fixed and supported, and a pressure contact with the heating body,
And a pressurizing member for bringing the recording material into close contact with the heating member via a film to heat and fix the visible image of the toner on the recording material. C) The surface temperature (T ₃ ) of the fixing film is determined by DSC. And a method for removing the fixing film from the fixing surface of the toner under a temperature condition higher than the measured endothermic temperature (T _D ) of the toner.

Further, the present invention provides a method for recording a visible image of a toner by using a fixedly supported heating element and a pressing member which is in pressure contact with the heating element and which makes the recording material adhere to the heating element via a film. A heating method in which the fixing film is heated and fixed, and the fixing film is peeled off from the fixing surface of the toner under conditions where the surface temperature (T ₃ ) of the fixing film is higher than the endothermic temperature (T _D ) of the toner measured by DSC. A toner for heat fixing used in a fixing method, wherein the toner contains at least a binder resin and a colorant, and the binder resin includes an aromatic vinyl-based monomer, an acrylate-based monomer, and methacrylic acid. Contains a polymer formed from one or more monomers selected from the group consisting of acid ester monomers, and THF
The present invention relates to a toner for heat fixing, which contains an insoluble component in an amount of 10 to 60% by weight based on the weight of a binder resin.

[Detailed description of the invention]

A structural feature of the heat fixing method of the present invention lies in a heat fixing method using a toner containing 10 to 60% by weight of a THF-insoluble component as a binder resin based on the binder resin. When a toner is produced by using a binder resin having a THF insoluble content of less than 10% by weight, pulverizability is extremely poor, and
It is disadvantageous in offset resistance. When a binder resin having a THF-insoluble content of more than 60% by weight is used, the offset resistance is improved, but when the toner is manufactured from such a binder resin, the toner is used as a recording material. This requires a high energy for heat-fixing, which is obviously disadvantageous.

Another object of the present invention is to provide a heat fixing toner comprising a binder resin containing a polymer having the above-mentioned improved crushability and offset resistance as a main component.

The THF-insoluble component in the present invention indicates the weight ratio of the polymer component (substantially crosslinked polymer) insoluble in the THF solvent in the resin composition in the toner, and indicates the weight ratio of the resin composition containing the crosslinkable component. It can be used as a parameter indicating the degree of crosslinking. The THF-insoluble matter is defined by a value measured as follows.

That is, 0.5 to 1.0 g of a toner sample is weighed (W
₁ g), put in a thimble filter paper (for example, No.86R manufactured by Toyo Roshi Kaisha), extract through a Soxhletley extractor, using 100 to 200 ml of THF as a solvent for 6 hours, evaporate the soluble components extracted with the solvent, and evaporate 100 g. Vacuum dried at ℃ for several hours, THF
Weigh the amount of soluble resin component (W ₂ g). The weight of a component other than the resin component such as a magnetic substance or a pigment in the toner is expressed as (W
₃ g). The THF-insoluble content is obtained from the following formula.

The binder resin in the present invention is preferably obtained by polymerizing one or more monomers selected from styrenes, acrylic acids, methacrylic acids and derivatives thereof from the viewpoint of developing characteristics and charging characteristics. Examples of monomers that can be used include styrenes such as styrene, α-methylstyrene,
Vinyl toluene, chlorostyrene and the like. As acrylic acids, methacrylic acids and their derivatives,
Acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n-acrylate
Acrylates such as tetradecyl, n-hexadecyl acrylate, lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate and the like can be mentioned. Similarly, methacrylic acid, methyl methacrylate, ethyl methacrylate, methacrylic acid Propyl acrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate,
Cyclohexyl methacrylate, phenyl methacrylate,
2-hydroxyethyl methacrylate, 2-methacrylic acid 2-
Examples include methacrylates such as hydroxypropyl, dimethylaminoethyl methacrylate, glycidyl methacrylate, and stearyl methacrylate. In addition to the above-mentioned monomers, a small amount of other monomers as long as the object of the present invention can be achieved, such as acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, vinylcarbazole, vinylmethylether, butadiene, isoprene, maleic anhydride, Maleic acid, maleic acid monoesters, maleic acid diesters, vinyl acetate and the like may be used.

As the crosslinking agent used in the binder resin of the present invention, 2
As a functional crosslinking agent, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 14-butanediol diacrylate,
1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol #
200, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type diacrylate (MANDA
Nippon Kayaku) and those obtained by replacing the above acrylates with methacrylates.

Pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropatriacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, polyethoxyf (Enyl) propane, diallyl phthalate, trially cyanurate, triallylsocyanurate, triallyl isocyanurate, triallyl trimetrate, diallylchlorendate and the like.

Among these, the styrene-based material containing styrene as a main component is relatively easy to design a material that satisfies the molecular weight and distribution characteristics of the binder resin defined in the present invention, and is inexpensive. Copolymers are preferably used.

The toner used in the present invention may contain, in addition to the above-mentioned binder resin component, the following compounds at a ratio smaller than the content of the binder resin component. For example, silicone resin, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax And so on.

Further, the toner used in the present invention may contain various release agents as necessary. For example, polyfluorinated ethylene, fluororesin, fluorocarbon oil, silicone oil, low molecular weight polyethylene, low molecular weight polypropylene and the like are used in an amount of 0.1 to 10% by weight based on the toner.

When the toner to be used is used as a magnetic toner containing magnetic fine particles, the magnetic fine particles may be any material that shows magnetism or is magnetizable, such as iron, manganese, nickel, cobalt, a metal such as chroma, magnetite,
Hematite, various ferrites, manganese alloys, and other ferromagnetic alloys are available.
Can be used. The amount of the magnetic fine particles contained in the magnetic toner is preferably 15 to 70% by weight (more preferably 25 to 45% by weight) of the total weight of the magnetic toner.

In addition, various substances can be added to the toner used in the present invention for the purpose of controlling coloring and charge. For example, carbon black, iron black, graphite, nigrosine, metal complexes of monoazo dyes, ultramarine, phthalocyanine blue,
Hansa Yellow, Benzine Yellow, quinacridone various lake pigments and the like.

Alternatively, colloidal birch as a fluidity improver may be contained in the toner in an amount of 10 to 40% by weight. Of course, the fluidity improver may be used as a mixture with the outside of the toner, and the amount added at that time is 0.2 to 5% by weight (based on the weight of the toner).

The toner used in the heat fixing method of the present invention is DS
As a result of measurement in the measurement range from 10 ° C. to 200 ° C. using C, a toner having a maximum endothermic peak first appearing, that is, an endothermic temperature (T _D ) of 40 ° C. to 120 ° C. is preferable.
Toners exhibiting characteristics of 5 ° C. to 100 ° C. are more preferred.

Further, the surface temperature (T ₃ ) of the film when the film is peeled from the toner fixing surface is preferably higher than the endothermic temperature (T _D ) from the viewpoint of the peelability of the film from the toner fixing surface, More preferably, it is preferable to release under conditions that are 30 ° C. or more (more preferably 40 to 140 ° C.) higher than the endothermic temperature (T _D ).

In the present invention, the maximum value of the endothermic peak is measured in accordance with ASTM D-3418-82. Specifically, 10 to 15 mg of toner is collected and stored at room temperature under nitrogen atmosphere.
After heating to 0 ° C at a heating rate of 10 ° C / min, hold at 200 ° C for 10 minutes, then quench to pre-treat the toner in advance, then hold at 10 ° C again for 10 minutes. Measure up to 200 ° C at a heating rate of ° C / min. In general, the data shown in FIG. 1 is obtained, and the maximum value of the endothermic peak that appears first is defined as the endothermic temperature (T _D ) in the present invention.

In the present invention, the heating element has a smaller heat capacity than a conventional heat roll and has a linear heating section, and the maximum temperature of the heating section is preferably 100 to 300 ° C.

Also, the film located between the heating element and the pressing member is
It is preferable to use a heat-resistant sheet having a thickness of 1 to 100 μm. Examples of the heat-resistant sheet include polyester, PET (polyethylene terephthalate), and PFA having high heat resistance.
In addition to polymer sheets such as (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer), PTFE (polytetrafluoroethylene) polyimide and polyamide, metal sheets such as aluminum, and laminated sheets composed of metal sheets and polymer sheets Used.

A more preferable film structure is that these heat-resistant sheets have a release layer and / or a low-resistance layer.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, but this does not limit the present invention in any way.

FIG. 2A is a structural view of the fixing device of the present embodiment.

(11) is a low-heat-capacity linear heating element fixed and supported on the device. As an example, an alumina substrate (12) with a thickness of 1.0 mm, a width of 10 mm and a length of 240 mm is coated with a resistance material (13) to a width of 1.0 mm. It is energized from both ends in the longitudinal direction. The energization is performed by applying a pulse having a pulse shape corresponding to a desired temperature and an energy release amount controlled by the temperature detecting element (14) with a pulse shape of 100 V DC and a cycle of 20 msec. The approximate pulse width is
It is 0.5 msec to 5 msec. In this way, the fixing film (15) moves in the direction of the arrow in the drawing while coming into contact with the heating element (11) whose energy and temperature are controlled. As an example of the fixing film, a heat-resistant film having a thickness of 20 μm, for example, a polyimide, polyetherimide, PES, PFA, and at least a PT
Release layer of conductive material added to fluororesin such as FE, PAF, etc.
m-coated endless film. In general, the film is driven with a driving roller (16) and a driven roller (17), and the film is moved in the direction of the arrow without wrinkles due to the tension and the driving by the driving roller (16) and the driven roller (17).

(18) is a pressure roller having a rubber elastic layer with good releasability, such as silicon rubber, which presses the heating element through the film with a total pressure of 4 to 20 kg and rotates by pressing against the film. The toner (20) is guided to the fixing unit by the entrance guide (21), and obtains a fixed image by the above-described heating.

Although the endless belt has been described above, as shown in FIG. 2 (b), a sheet feed shaft (24) and a take-up shaft (27) may be used, and the fixing film may be an endless film.

In addition, as an image forming apparatus, a copying machine, a printer, a fax,
This is applicable to all fixing devices that form an image using toner such as.

If the temperature detected by the temperature detection element (14) in the low heat capacity linear heating member (11) is T _1, the surface temperature T ₂ of the film (15) opposed to the resistance material (13) than T ₁ to about 10 ~ 30 ℃ lower. The film surface temperature T ₃ in the portion films (15) is peeled from the fixed toner surface is substantially equal to the temperature and the temperature T _2.

Examples of the synthesis of the binder resin according to the heat fixing method of the present invention are shown below.

Synthesis example (1) Polyvinyl alcohol partially saponified 0.1 to the above mixture
170 parts by weight of water in which parts by weight were dissolved were added to obtain a suspension dispersion. The above-mentioned suspension dispersion was added to a reactor charged with 15 parts by weight of water and purged with nitrogen, and subjected to a suspension polymerization reaction at a reaction temperature of 78 ° C for 12 hours. After completion of the reaction, the mixture was separated by filtration to obtain a dehydrated, styrene-n-butyl acrylate copolymer composition. The composition comprises THF
The insolubles and the THF-solubles were uniformly mixed, and the obtained resin composition had a THF-insoluble content (measured using 24 mesh powder and 60 mesh powder) of 53 wt%.

Synthesis example (2) Polyvinyl alcohol partially saponified 0.1 to the above mixture
170 parts by weight of water in which parts by weight were dissolved were added to obtain a suspension dispersion. The suspension dispersion was added to a reactor which was filled with 15 parts by weight of water and purged with nitrogen, and subjected to a suspension polymerization reaction at a reaction temperature of 82 ° C. for 12 hours. After completion of the reaction, the mixture was filtered off, dehydrated and dried to obtain a styrene-2-ethylhexyl methacrylate copolymer composition. In the composition, a THF-insoluble component and a THF-soluble component were uniformly mixed, and a THF-insoluble component (measured with a powder of 24 mesh, 60 mesh) of the obtained resin composition was 24% by weight. .

Example (1) After mixing the above ingredients with a Hensiel mixer, 150
The mixture was kneaded with a two-roll mill heated to 20 ° C for 20 minutes. After the kneaded product was allowed to cool, it was roughly pulverized with a cutter mill, then pulverized using a fine pulverizer using a jet stream, and further classified using an air classifier to obtain a black fine powder having a volume average particle size of 11.6 μm. Was.

0.4 parts by weight of colloidal silica fine powder was dry-mixed with 100 parts by weight of the black fine powder to obtain a developer (toner). Further, T _D of the toner was 72 ° C..

Next, in order to evaluate the fixing property and the anti-offset property by the heat fixing method of the present invention shown in FIG. 2 (a), a test machine was used in which the fixing machine of Canon Copier FC-5 was removed. An unfixed image was imaged.

Evaluation of the fixing test and anti-offset property by adjusting the temperatures T ₁ in the 2 (a) thermometry elements of the heating body shown in FIG. 14 to 200 ° C., the fixing film (15) is rotated at 40 mm / sec I did it. The pressure was adjusted so that a pressure of 5 kg was applied between the heating element (11) and the pressure roller (18). Further, the temperature T _{2 at} this time was 183 ° C., and the temperature T ₃ was 180 ° C.

The fixability was measured by applying a load of 50 g / cm ² , rubbing the fixed image with silbon paper, and decreasing the image density before and after rubbing (%).
Indicated by The evaluation image was obtained by passing unfixed images continuously for 200 sheets, and performing the first, 10, 50, 100, and 200th fixed images.

The offset resistance was evaluated by passing an unfixed image having an image area ratio of about 5%, and determining the number of sheets on which an image was stained.

As a result, the fixability is almost averaged up to the 200th sheet,
It was as good as about 1%. Also, the offset resistance is
No staining was observed on the image even after the fixing of 10,000 sheets, and little toner adhesion was observed on the surfaces of the fixing film and the pressure roller, which was good.

 The heating and fixing device of the present invention reached 200 ° C. in about 2 seconds.

Example (2) After pre-mixing the above ingredients with a Hensiel mixer,
The mixture was kneaded with a two-roll mill heated to 20 ° C for 20 minutes. After the kneaded product was allowed to cool, it was coarsely pulverized with a cutter mill, then pulverized using a fine pulverizer using a jet stream, and further classified using an air classifier to obtain a black fine powder having a volume average particle size of 11.3 μm. Was.

0.4 part by weight of hydrophobic colloidal silica fine powder was dry-mixed with 100 parts by weight of the black fine powder to obtain a developer (toner). The T _{D of} this toner was 75 ° C.

Next, in order to evaluate the fixing property and the offset resistance by the heat fixing method of the present invention shown in FIG. 2 (a), a test machine was used in which the fixing machine of the Canon NP-6650 was removed. An unfixed image was imaged.

Evaluation of the fixing test and anti-offset property by adjusting the temperatures T ₁ in the 2 (a) thermometry elements of the heating body shown in FIG. 14 to 215 ° C., the fixing film (15) is rotated at 200 mm / sec I did it. The pressure was adjusted so that a pressure of 20 kg was applied between the heating element (11) and the pressure roller (18). Further, the temperature T _{2 at} this time was 190 ° C., and the temperature T ₃ was 188 ° C.

The fixability was measured by applying a load of 50 g / cm ² , rubbing the fixed image with silbon paper, and decreasing the image density before and after rubbing (%).
Indicated by The evaluation image was obtained by passing unfixed images continuously for 200 sheets, and performing the first, 10, 50, 100, and 200th fixed images.

The offset resistance was evaluated by passing an unfixed image having an image area ratio of about 5%, and determining the number of sheets on which an image was stained.

As a result, the fixability is almost averaged up to the 200th sheet,
It was as good as about 3%. Also, the offset resistance is
No staining was observed on the image even after the fixing of 10,000 sheets, and little toner adhesion was observed on the surfaces of the fixing film and the pressure roller, which was good.

Incidentally, the heat fixing machine of the present invention reached 215 ° C. in about 2 seconds.

Example (3) After pre-mixing the above ingredients with a Hensiel mixer,
The mixture was kneaded with a two-roll mill heated to 20 ° C for 20 minutes. After the kneaded product was allowed to cool, it was coarsely pulverized by a cutter mill, pulverized using a fine pulverizer using a jet stream, and further classified using an air classifier to obtain a black fine powder having a volume average particle diameter of 12.4 μm. Was.

0.4 parts by weight of colloidal silica fine powder was dry-mixed with 100 parts by weight of the black fine powder to obtain a developer (toner). Further, T _D of the toner was 69 ° C..

Next, in order to evaluate the fixing property and the offset resistance by the heat fixing method of the present invention shown in FIG. 2 (a), it was determined using an experimental machine in which the fixing machine of Canon Copy FC-5 was removed. The image of the ringing image was output.

Evaluation of the fixing test and anti-offset property by adjusting the temperatures T ₁ in the 2 (a) thermometry elements of the heating body shown in FIG. 14 to 200 ° C., the fixing film (15) is rotated at 50 mm / sec I did it. The pressure was adjusted so that a pressure of 15 kg was applied between the heating element (11) and the pressure roller (18). Further, the temperature T _{2 at} this time was 184 ° C., and the temperature T ₃ was 183 ° C.

The fixability was measured by applying a load of 50 g / cm ² , rubbing the fixed image with silbon paper, and decreasing the image density before and after rubbing (%).
Indicated by The evaluation image was obtained by passing unfixed images continuously for 200 sheets, and performing the first, 10, 50, 100, and 200th fixed images.

The offset resistance was evaluated by passing an unfixed image having an image area ratio of about 5% and determining the number of sheets on which the image was stained.

As a result, the fixability is almost averaged up to the 200th sheet,
It was as good as about 2%. Also, the offset resistance is
No staining was observed on the image even after the fixing of 10,000 sheets, and little toner adhesion was observed on the surfaces of the fixing film and the pressure roller, which was good.

Incidentally, the heat fixing machine of the present invention reached 200 ° C. in about 2 seconds.

Example (4) After pre-mixing the above ingredients with a Hensiel mixer,
The mixture was kneaded with a two-roll mill heated to 20 ° C for 20 minutes. After the kneaded product was allowed to cool, it was coarsely pulverized with a cutter mill, then pulverized using a fine pulverizer using a jet stream, and further classified using an air classifier to obtain a black fine powder having a volume average particle size of 12.0 μm. Was.

0.4 parts by weight of colloidal silica fine powder was dry-mixed with 100 parts by weight of the black fine powder to obtain a developer (toner). Further, T _D of the toner was 77 ° C..

Next, in order to evaluate the fixing property and the offset resistance by the heat fixing method of the present invention shown in FIG. 2 (a), a test machine was used in which the fixing machine of the Canon NP-6650 was removed. An unfixed image was imaged.

Evaluation of the fixing test and anti-offset property by adjusting the temperatures T ₁ in the 2 (a) thermometry elements of the heating body shown in FIG. 14 to 215 ° C., the fixing film (15) is rotated at 200 mm / sec I did it. The pressure was adjusted so that a pressure of 18 kg was applied between the heating element (11) and the pressure roller (18). Further, the temperature T _{2 at} this time was 195 ° C., and the temperature T ₃ was 193 ° C.

The fixability was measured by applying a load of 50 g / cm ² , rubbing the fixed image with silbon paper, and decreasing the image density before and after rubbing (%).
Indicated by The evaluation image was obtained by passing unfixed images continuously for 200 sheets, and performing the first, 10, 50, 100, and 200th fixed images.

The offset resistance was evaluated by passing an unfixed image having an image area ratio of about 5%, and determining the number of sheets on which an image was stained.

As a result, the fixability is almost averaged up to the 200th sheet,
It was as good as about 2%. Also, the offset resistance is
No staining was observed on the image even after the fixing of 10,000 sheets, and little toner adhesion was observed on the surfaces of the fixing film and the pressure roller, which was good.

Incidentally, the heat fixing machine of the present invention reached 215 ° C. in about 2 seconds.

Comparative Example (1) Using the toner shown in Example (1), an image was formed with a fixing machine of NP-1215 (manufactured by Canon Inc.) from which the cleaning mechanism of the fixing roller was removed, and a fixing test was performed.

The fixability was a little inferior with a density reduction rate of about 15%, and the offset property was clearly inferior because the image was stained at 4,500 sheets. It took about one minute for the fixing device to reach 200 ° C.

Comparative Example (2) The same fixing test and evaluation of the offset resistance as in Example (1) were carried out except that the monomer composition ratio of the toner used in Example (1) was changed to that shown below. went.

And the THF insoluble content was 82%.

As a result, the fixing property was clearly inferior at a reduction rate of the image density of about 25%, and the offset resistance was stained on the image after passing 1700 sheets, which was also clearly inferior. Was something.

Comparative Example (3) Using the toner of Example (3), the fixing property and the offset resistance were evaluated using an FC-5 (manufactured by Canon Inc.) fixing machine from which the fixing roller cleaning mechanism was removed. The evaluation was performed by the same method as in Example (1). As a result, the fixing property was inferior to about 15%, and the offset resistance was clearly inferior because the image was stained when 900 sheets were passed.

It took about one minute for the fixing device to reach 200 ° C.

As is clear from the above Examples and Comparative Examples, good results were obtained when the heat fixing method and the heat fixing toner of the present invention were used, and were clearly superior to those in other cases. is there.

[Brief description of the drawings]

FIG. 1 is a graph showing an endothermic peak of the toner. FIG. 2A is a schematic sectional view of a fixing device for carrying out the fixing method of the present invention, and FIG. 2B is a sectional view for carrying out a fixing method of another embodiment of the present invention. FIG. 2 is a schematic sectional view of a fixing device. 11 Heating element 12 Alumina substrate 13 Resistive material 14 Temperature sensor 15 Fixing film 16 Driving roller 17 Driven roller 18 Pressure roller 19 Recording material 20 To be determined Toner visible image 21 …… Entrance guide

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-68766 (JP, A) JP-A-63-223662 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 9/087 G03G 15/20

Claims (12)

(57) [Claims] 1. A heat fixing method for heating and fixing a visible image of a toner on a recording material using a toner containing at least a binder resin and a colorant, wherein: a) an aromatic vinyl monomer, an acrylate ester monomer and A toner formed from one or more monomers selected from the group consisting of methacrylic acid ester monomers, containing a polymer as a binder resin,
The binder resin has a THF insoluble content of 1 based on the weight of the binder resin.
Using a toner containing 0 to 60% by weight; b) a heating member fixed and supported;
And a pressurizing member for bringing the recording material into close contact with the heating member via a film to heat and fix the visible image of the toner on the recording material. C) The surface temperature (T ₃ ) of the fixing film is determined by DSC. A heat fixing method, wherein the fixing film is peeled off from a fixing surface of the toner under a temperature condition higher than an endothermic temperature (T _D ) of the toner to be measured. 2. The fixing film is peeled from the fixing surface of the toner under the condition that the surface temperature (T ₃ ) of the fixing film is higher than the endothermic temperature (T _D ) of the toner measured by DSC by 30 ° C. or more. 2. The heat fixing method according to claim 1, wherein the heat fixing is performed. 3. The toner has an endothermic temperature (T _D ) of 40 to 120.
3. The heat fixing method according to claim 1, wherein the temperature is ℃. 4. The heat fixing method according to claim 1, wherein the toner further contains a release agent in addition to the binder resin and the colorant. 5. The heat fixing method according to claim 1, wherein the fixing film is a heat-resistant film having a release layer containing a conductive material on a toner fixing surface side. 6. A pressure for bringing the recording material into close contact with the heating member via the fixing film by the pressure-contact member is a total pressure of 4 to 20.
The heat fixing method according to claim 1, wherein the weight is kg. 7. A recording medium, comprising: a heating member fixed and supported; and a pressing member which is in pressure contact with the heating member and closely contacts the recording material to the heating member via a film. The fixing film surface temperature (T ₃ ) is DSC
A heat fixing toner used in a heat fixing method of peeling the fixing film from a fixing surface of the toner under a temperature condition higher than an endothermic temperature (T _D ) of the toner measured by the method, It contains at least a binder resin and a coloring agent, and the binder resin is formed from one or more monomers selected from the group consisting of aromatic vinyl monomers, acrylate monomers and methacrylate monomers. A heat fixing toner comprising a polymer containing a polymer and 10 to 60% by weight of a THF-insoluble component based on the weight of the binder resin. 8. The toner according to claim 1, wherein the surface temperature (T ₃ ) of the fixing film is 30 ° C. or more higher than the endothermic temperature (T _D ) of the toner measured by DSC. The heat fixing toner according to claim 7, which is used in a heat fixing method of peeling a fixing film. 9. The toner has an endothermic temperature (T _D ) of 40 to 120.
9. The heat fixing toner according to claim 7, wherein the toner temperature is ℃. 10. The heat fixing toner according to claim 7, wherein the toner further contains a release agent in addition to the binder resin and the colorant. . 11. A heat fixing method using a heat-resistant film having a release layer containing a conductive material on a toner fixing surface side as said fixing film.
11. The toner for heat fixing according to any one of items 1 to 10. 12. The pressure for bringing the recording material into close contact with the heating member via the fixing film by the pressure contact member is a total pressure of 4 to 4.
12. The heat fixing toner according to claim 7, wherein the toner is used in a heat fixing method weighing 20 kg.